Joseph s



.l. S. ALLEN.

' TELEPHONE SYSTEM.

APPLICA'HON HLED um 1s. ms.

1,321, 181 Patented Nov. 11, 1919.

B W WmiiOPSLM' J HZ'ZZrrzzeg UNITED STATES JOSEPH S. ALLEN, OF CHICAGO, ILLINOIS, ASSIGNOR TO KELLOGG SWITUHIBOARD AND SUPPLY COMPANY, OF CHICAGO, ILLIN 01S, A QOBPORATION OI ILLINOIS.

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To all whom it may concern:

Be it known that I, JOSEPH A m nli, a citizen ofthe United istats-of fimerie'ag residing in Chicago, county of Gook, and State of Illinois, have invented certaln new and useful Improvements in Telephone Systoms, of which the following is a specification.

My invention relates telephone systems in which link or trunk circuits are employed, and has to do more particularly with manually operated systems in which the line and supervisory signals located at the central oflice are controlled'by local batteries located at the subscribers substation, and has for its object a novel an'd improved system of the above type.

In systems ofthis character local battery is used at the substation for talking purposes, which battery either alone or in conjunction with an additional batteryis used through the medium of a passing contact maker for sending a current impulse of a certain time interval to operate suitable signals at the efcliangei' In systems using apparatus of this kind, it is desirable to send an impulse upon the upward movement'of the switch-hook, to operate a line Signal to notify the operatorthat a connection is desired, and to transmit a second impulse upon'the downward movement of the switchhook to operate a supervisory signal for su pervisory pur oses. In the presentproposed systems it has been found that'one of the principal undesirable features 'is'that when the called subscriber answcrsa callhe causes the calling supervisory signal of the connected cord circuit to, be operated by the upward movement of his switch-hook.

It is the object of my invention to produce improved system of the character described which will obviate the above and other undesirable features and embody desirable features of construction and circuit arrangement in a'simple, eflicient and economical manner; and to the accomplishment of this object the invention consists in the novel details of construction 'iaIid' circuit arrangementsas' hereinafter described and pointed out in the appended claims;

Referring to the accompanying drawing, I have illustrated the preferred embodiment of my invention by showing substations'A and D terminating in line circuits 'L and L respectively, each comprising theusuai jack Q ;Se s caaqn of Lsi rr si l et ent- Applicationlflled m 16, 1915. ser al no. 40,178.

Pat-entedNov. 11, 1919.

and line signal. The substation A comprises the usual receiver -2, transmitter 3, induction coil 4, bells 5, battery 6 and switch-hook In addition the substation comprises a self-locking relay 8 mechanically connected with the switch-hook 7, contacts!) and 10 and an auxiliary signaling battery 11. The relay 8' Wl1i0l'1' responds to alternating cur.- rent, upon energizing, attracts its armature 12 and permits the spring 14 to open contact with spring 15. The arm 16 is insulatingly connected to the hook switch lever 7 in such a manner that upon said hook switch lever reaching the extent of its oil-normal movement, the hook portion 17 of the lever 16 engages the member 14 and permits the armaturelfl of the relay 8 to return to normal and close contact between the springs '14 and 15. The contact 10 is insulatingly secured to'the hook switch lever 7 and is adapted to engage the contact 9 upon both the upward and downward stroke of said hook-switch lever 7. That is, the contact 10 makes passing contact with the contact point 9 upon each movement of theswitchhook. The auxiliary battery 11 and talking battery 6 are adapted to be connected in series and bridged across the line when the contacts 9 and 10 are momentarily closed thereby operating the line drop or the supervisory signal as the case maybe.

' The link circuit C comprises the usual answering and calling plugs AP and CP inductively united through the heavily marked conductors. Associated with the answering plug AP is an answering supervisory drop ASD. Associated with the calling plug ,CP is a calling supervisory drop CSD. A

ringing andvlistening key 18 is provided 'foiconnecting the operators set'O'to 'the straiids'of the link circuit C and for bridging the ringing generator G across the conductors of the called subscribers line. The substation D and its line circuit L are similar in all respects to the substation A and its line circuit L Having described in general the apparatus used in establishing a connection between a calling and called substation, I Willnow describe the preferred embodiment of my invention more in detail. 7 Assuming that the subscriber at substation A Wishes to converse with the subscriber at substation D, the subscriber by removing his receiver 2 from the switch-hook sergizing,

7 allows the contact 10 to momentarily engage the contact 9 thus bridging the batteries 6 and 11 across the calling subscribcrs line over a path extending from one terminal of the battery 11 through the springs 14 and 15, contacts 10 and 9 one limb of the calling subscribers line, line drop LD, normal contact 19, the opposite scriber at substation I is desired, inserts the calling plug CP into jack J of the-linecircuit L thereby disconnecting the line drop .LD from across the called subscribers line.

The operator (next e5 the ringing and listening, key 18 to lrige the generator G across the limbs of called subscribers line over a path extending from ungrounded terminal of generator G, through the tip conductor of the calling plug CP and pick J", relay 8*, signal receiving device 5 sleeve conductors of jack J and calling plug GP to ground and back to the opposit terminal of the generator G. TherelayS upon enattracts its armature 12 and allows the spring 14 to break contact with spring 15. The operator then restores the ringing key to normal and disconnects the generator G and bridges the calling supervisory drop'CSD across the limbs of the called subscribers line. The called subscriber in answer to the si al that he has received, removes his receiver from the switch-hook thereby allowing the contacts 9 and 10 to momentarily engage, but owing to the fact that contact 15 is out of engagement with contact 14, the auxiliary battery 11 and battery 6 subscribers line. The switch-hook 7 upon reaching the extent of its upward movement, causes the arm 16 to lift the spring 14 from in front of the armature 12 of relay 8 and allows the said armature to restore to normal whereby the contacts 14 and 15 are again closed. The subscribers may now carry on conversation over the heavily marked conductors.

The subscribers at substations A and I) having finished conversation, replace their receivers upon their respective switchhooks. The replacing of the receiver at substation A permits the contacts 9 and 10 to again momentarily engage to bridge batteries 11 and 6 across the limbs of the I have are not bridged across the called their respective jacks J and J thereby again bridging theline drops LD and LD across their respective lines.

From the foregoing it is thus seen that rovided a local battery system in which t e signaling current is all supplied from the subscribers stations and in which accurate double supervisory is provided.

Although I have chosen a preferred embodiment for the purpose of illustrating my invention, yet I do not wish to be limited to the same as many changes and modifications may be made by one skilled in the art with out departing from the spirit and scope of my invention, as set forth in the appended claims.

Having described my invention, What I claim as new and desire to secure by United States Letters Patent, is:

1. A telephone system comprising a subscribers line provided with a substation, a link circuit for connection to said line, a supervisorysignal for said link circuit, substation controlled means for operating signal, means for si naling said substation, and means contro led by said signaling means for preventing an effective operation of said substation controlled means when the subscriber responds.

2. A telephone system comprising a sub scribersline, a substation therefor, a signaling battery for said substation, a pair of contacts under substation control, a signal at the central otlice, means for connecting said battery through said contacts to operate said signal, and automatic means located at the substation for preventing the operative connection of said battery through said contacts.

3. A telephone system comprising a subscribers line, a substation therefor, a signaling battery for said substation, a pair of contacts adapted to be operated by the upward and downward movement of the switch-hook lever, a signal at the central office, means for connecting said batte through said contacts to operate'said signa and means for preventing the operative connection of said battery through said contacts to operate said signa saidlast means compris ng a relay responsive to signaling current.

4. A substation of the character described comprising a relay connected in the signaling circuit of said substation, a signaling battery for said substation for operating a signal at the central oilice, and means controlled from the said central oflice for operating said relay when actuating the call bell at said substation, thereby preventing the use of said signalin battery to operate said signal when the su scriber responds to the call and operates his switch hook.

5. A telephone system comprising a sub-- scribers substation, a relay connected in the signaling circuit of said substation, a control circuit at said substation, si naling means controlled from the central o co for operating said relay whereby said relay renders said control circuit ineffective and means controlled by the subscriber at the substation for restoring said relay to normal, thereby again rendering said control circuit effective.

6. A telephone system comprisin a subscribers substation, a self-locking re ay connected in the signaling circuit of said substation, a control circuit at said substation, signaling means controlled from the central ollice for operating said relay whereby said relay renders said control circuit ineffective, and means for subsequently unlocking said relay thereby rendering said control circuit eifective.

7. In a telephone system, a subscribers substation provided with a signaling battery, a relay at said substation, a supervisory signal at the central oflice, a switchhook lever for momentarily connecting said battery to said signal, and means controlled from the central ofiice for operating said relay, thereby preventing an operation of said signal when the said switch-hook lever is operated.

8. A telephone system comprising a subscribers line, a substation therefor provided with a switch hook, at line signal for said line, a link circuit provided with a supervisory signal, means for operatin said signals, means for connecting the saiil link circuit to the said line and for preventing an operation of said line signal, and substation means controlled from the central ofiice for preventing the operation of said supervisory signal when the subscriber at the said substation operates his switch-hook.

9. A telephone system comprising a subscribers line, a substation therefor provided with a switch hook, a link circuit provided with a supervisory signal, 0 )erator controlled means for connecting tie said link circuit to the said line, means for operating said signal, and relay means controlled from the central office for preventing the operation of said supervisory signal when the subscriber at the said substation operates his switch-hook.

10. A telephone system comprising it called subscribcrs line, a link circuit for connection to said line, signaling current controlled from said link circuit, supervisory means bridged across the strands of said link circuit, a signalinor battery at the substation of said line, ancl means responsive to the said signaling current for preventing the said signaling battery from afl'ecting said supervisory means when the said subscriber responds.

11. In a tele hone system, the combination of a called su scribers line and an operators link circuit connected thereto, signaling means for said link circuit, a signaling battery for said substation, and means at the substation responsive to the said signaling means for preventing the connection of said signaling battery to the said link circuit.

12. A telephone system including a subscribers line, a drop bridged across said line, a signaling battery at the substation of said line adapted to be bridged across said line for operating said drop when the subscriber at the substation initiates a call, a link circuit adapted to be connected to said line, a supervisory signal for-said link circuit, substation controlled means for operatin said supervisory signal, means to prevent t 1e operation of said line drop when the substation is used as a called line, and automatic means to prevent the operation of said supervisory signal when the substation is used as :1 called substation.

13. A telephone system including a subscribers line, a substation therefor, a sig nal battery for said substation, a pair of contacts under substation control, a supervisory signal at the central exchange, means for operating said pair of contacts to connect said battery to the subscribers line to operate said signal, and means for preventing the operative connection of said battery through said contacts to operate said signal, said last means comprising an electromag net at the substation.

14. A telephone system including a subscriber-s telephone line provided with a substation, a call signal device therefor, a link circuit for connection to said line, a supervisory signal for said link circuit, means controlled at said substation to operate said supervisory signal, means for operating said call signal device, and mechanism controlled by said last means for rendering ineffective the operation of said first means, but permitting the establishment of a conversational circuit including said substation.

15. A telephone system including a subscribers telephone line extending to the central exchange, a relay connected in the circuit of said line and located at the substation thereof, a signal at the central office, means controlled at said substation for operating said signal, and signaling means controllable at the central oilice for operating said relay to render said first means ineffective when the subscriber responds, but permitting the establishment of a conversational circuit including said substation.

16. A telephone system including a subscribers line, a substation connected to said line, a lock-out device located at said substation, a link circuit at the central oliice for connection to said line. a supervisory device for said link circuit, a source of signaling current associated with said link circuit, means for connecting said current to said line to operate the call bell at said subscribers substation and to operate said lockout means to render said substation inefi'ective to operate said supervisory device when the subscriber responds, but permitting establishment of a conversational circuit including the talking apparatus at the substation.

17. A telephone s stem including a subscribers line, an in ividual signal for said line, signaling means located at the substa- Gopien of this patent may be obtained tor tion upon said line for operating said in dividual signal when a subscriber at the substation initiates a call, a. call signal device, a link circuit adapted to be connected to said line, a supervisory signal for said link circuit, said signal being controlled by said substation signaling means, and means located at the substation responsive to a source of witnesses.

JOSEPH S. ALLEN.

Vi itnesses GEORGE A. YANOCHOWSKI, B. OBRIEN.

five cents each, by undressing the Commissioner of Patents, Wellington, 1). 0."

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